U.S. patent application number 15/514694 was filed with the patent office on 2018-07-26 for thermoplastic article with active agent.
The applicant listed for this patent is KIMBERLY-CLARK WORLDWIDE, INC.. Invention is credited to Paige N. Anunson, David William Koenig, Andrew Mark Long, David J. Tyrell, Rebecca Ann Vongsa, Peiguang Zhou, Shiming Zhuang.
Application Number | 20180207313 15/514694 |
Document ID | / |
Family ID | 52744522 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180207313 |
Kind Code |
A1 |
Zhuang; Shiming ; et
al. |
July 26, 2018 |
THERMOPLASTIC ARTICLE WITH ACTIVE AGENT
Abstract
An extruded water-soluble article is made from homogeneous
material that includes a water-soluble polymer having an extrusion
temperature of 50 to 150.degree. C. This relatively low extrusion
temperature is compatible with actives that would otherwise be
destroyed in a high temperature extrusion process. The article
further includes between 0.1% to 50% by weight of an active agent.
Potential active agents include, isothiazolone, alkyl dimethyl
ammonium chloride, a triazine, 2-thiocyanomethylthio benzothiazol,
methylene bis thiocyanate, acrolein, dodecylguanidine
hydrochloride, a chlorophenol, a quaternary ammonium salt,
gluteraldehyde, a dithiocarbamate, 2-mercatobenzothiazole,
para-chloro-meta-xylenol, silver-based compounds, chlorohexidine,
polyhexamthylene biguanide, a n-halamine, triclosan, a
phospholipid, an alpha hydroxyl acid,
2,2-dibromo-3-nitrilopropionamide, 2-bromo-2-nitro-1,3-propanediol,
iodine, bromine, hydrogen peroxide, chlorine dioxide, ozone, a
botanical oil, a botanical extract, chlorine, sodium hypochlorite,
farnasol, inulin, prebiotics, benzalkonium chloride, and
combinations thereof. The article may be in the form of a film, and
in one potential use, be disposed in an absorbent article.
Inventors: |
Zhuang; Shiming; (Menasha,
WI) ; Vongsa; Rebecca Ann; (Neenah, WI) ;
Zhou; Peiguang; (Appleton, WI) ; Long; Andrew
Mark; (Appleton, WI) ; Koenig; David William;
(Menasha, WI) ; Tyrell; David J.; (Milwaukee,
WI) ; Anunson; Paige N.; (Neenah, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KIMBERLY-CLARK WORLDWIDE, INC. |
Neenah |
WI |
US |
|
|
Family ID: |
52744522 |
Appl. No.: |
15/514694 |
Filed: |
April 1, 2015 |
PCT Filed: |
April 1, 2015 |
PCT NO: |
PCT/US2015/023866 |
371 Date: |
March 27, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61L 15/225 20130101;
A61L 2300/216 20130101; A61L 15/62 20130101; A61F 2013/530233
20130101; A61F 13/15211 20130101; A61L 2300/208 20130101; A61L
15/24 20130101; A61L 2300/404 20130101; A61L 15/28 20130101; A61L
15/26 20130101; A61F 13/00063 20130101; A61L 15/44 20130101; C08L
31/04 20130101; A61F 2013/15235 20130101; A61L 2300/30 20130101;
C08K 5/0058 20130101; C08L 3/02 20130101; A61L 15/46 20130101; A61L
2300/232 20130101; A61F 13/8405 20130101; C08L 29/04 20130101; A61F
2013/00642 20130101; C08K 5/0058 20130101; C08L 101/14 20130101;
C08L 29/04 20130101; C08K 5/0058 20130101; C08L 3/02 20130101; C08L
29/04 20130101; C08K 5/0058 20130101; C08L 31/04 20130101 |
International
Class: |
A61L 15/46 20060101
A61L015/46; A61L 15/24 20060101 A61L015/24; A61L 15/26 20060101
A61L015/26; A61L 15/28 20060101 A61L015/28; A61L 15/62 20060101
A61L015/62; A61F 13/84 20060101 A61F013/84 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2014 |
US |
PCT/US2014/057798 |
Claims
1. An extruded water-soluble article comprising: a homogeneous
material comprising a water-soluble, polymer having an extrusion
temperature of 50 to 150.degree. C.; and between 0.1% to 50% by
weight of an active agent.
2. The extruded water-soluble article of claim 1, wherein the
polymer is selected from the group consisting of polyvinyl alcohol
(PVOH), polyethylene oxide (PEO), polyethylene glycol (PEG),
polyacylate (acid), polyacylamide, polyester, water soluble
thermalplastic starch, and a combination thereof.
3. The extruded water-soluble article of claim 1, wherein the
polymer is an amorphous polyvinyl alcohol matrix having an
extrusion temperature of 90.degree. C. to 125.degree. C.
4. The extruded water-soluble article of claim 3, wherein there is
1% to 30% by weight of the active agent incorporated into the
polyvinyl alcohol matrix.
5. The extruded water-soluble article of claim 1 further comprising
up to 50% starch by weight.
6. The extruded water-soluble article of claim 1 further comprising
up to 30% by weight of ethylene vinyl acetate (EVA).
7. The extruded water-soluble article of claim 1, wherein the
article is a film.
8. The extruded water-soluble article of claim 7, wherein the film
has a water dissolution speed from 5 seconds to 30 minutes as
determined by a Water Dissolution Test of the present
disclosure.
9. The extruded water-soluble article of claim 7, wherein the film
has a basis weight of 5 gsm to 500 gsm.
10. The extruded water-soluble article of claim 7, wherein the film
has a tensile strength of 0.5 MPa to 50 MPa according to a Tensile
Test of the present disclosure.
11. The extruded water-soluble article of claim 7, wherein the film
has an elongation of 2% to 200% according to a Tensile Test of the
present disclosure.
12. The extruded water-soluble article of claim 1 wherein the
active agent is Yucca spp.
13. The extruded water-soluble article of claim 1 wherein the
active agent is inulin.
14. The extruded water-soluble article of claim 1 wherein the
active agent is selected from the group consisting of
isothiazolone, alkyl dimethyl ammonium chloride, a triazine,
2-thiocyanomethylthio benzothiazol, methylene bis thiocyanate,
acrolein, dodecylguanidine hydrochloride, a chlorophenol, a
quaternary ammonium salt, gluteraldehyde, a dithiocarbamate,
2-mercatobenzothiazole, para-chloro-meta-xylenol, silver-based
compounds, chlorohexidine, polyhexamthylene biguanide, a
n-halamine, triclosan, a phospholipid, an alpha hydroxyl acid,
2,2-dibromo-3-nitrilopropionamide, 2-bromo-2-nitro-1,3-propanediol,
iodine, bromine, hydrogen peroxide, chlorine dioxide, ozone, a
botanical oil, a botanical extract, chlorine, sodium hypochlorite,
and combinations thereof.
15. The extruded article of claim 1 wherein the active agent is
benzalkonium chloride.
16. The extruded article of claim 1 wherein the active agent is
farnesol.
17. The extruded water-soluble article of claim 1 wherein there is
0.1% to 30% by weight of the active agent incorporated into the
polymer.
18. A personal absorbent article comprising: an absorbent member
disposed between a water-impermeable backsheet and a
water-permeable liner, wherein the liner has a body-facing surface
and an opposite garment-facing surface; and the extruded
water-soluble article of claim 1 attached to the liner or a surface
of the absorbent member adjacent the liner.
19. A disposable article having the film of claim 7 attached
thereto, wherein the disposable article is a non-woven
substrate.
20. An absorbent member comprising the film of claim 7, and an
absorbent member disposed between a backsheet and a liner; wherein
the film is disposed between the liner and the absorbent member or
on top of the liner.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority as a continuation-in-part
of International Application No. PCT/US14/57798, filed on Sep. 26,
2014, which claims the benefit of Application No. 61/884,574, filed
on Sep. 30, 2013. The entirety of Application No. 61/884,574 and
International Application No. PCT/US14/57798 are incorporated
herein by reference.
BACKGROUND
[0002] Active agents, such as antimicrobial agents or antifungal
agents, have been used in conjunction with many products. In
particular, since viral outbreaks such as SARS, bird flu and
norovirus have been widely publicized, consumers have an increased
interest in a wide array of products having an antimicrobial agent
applied thereto; products such as wipes, shoe inserts, athletic
clothing, personal care products, hospital equipment, sports
equipment, etc. Products such as absorbent articles meant for
bodily fluids (e.g. disposable diapers, pads and incontinence
garments) may offer an odor-control benefit when an antimicrobial
agent is applied thereto.
[0003] Currently, the application of an antimicrobial or antifungal
agent onto a select portion of an absorbent personal-care article
is achieved by applying it as a lotion, cream, or spray
formulation. However, due to the application method, and/or the
incompatibility and/or poor solubility of the active agent(s) in
the formulation, getting effective concentrations of the active
agents onto the personal care product is challenging.
[0004] There remains a need for a better way to apply an active
agent such as an antimicrobial agent or antifungal agent to an
absorbent personal-care product. For instance, there is a desire
for an application method that does not require several additional
steps in the manufacture of such a product (e.g. spraying,
slot-coating, or the like). There is also a desire for a method of
applying an active agent to such a product so that it demonstrates
higher efficacy than is currently available.
SUMMARY
[0005] A first aspect of the present disclosure is an extruded
water-soluble article made from a homogeneous material that
includes a water-soluble polymer having an extrusion temperature of
50 to 150.degree. C. The article further includes between 0.1% to
50% (by total article weight) of an active agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The foregoing and other features and aspects of the present
disclosure and the manner of attaining them will become more
apparent, and the disclosure itself will be better understood by
reference to the following description, appended claims and
accompanying drawings, where;
[0007] FIG. 1 is a chart showing the dissolution time for one
embodiment of a film according to the present disclosure;
[0008] FIGS. 2-4 are charts showing zone of inhibition on films
containing various biocides of the present disclosure;
[0009] FIG. 5 is a chart showing the stress and strain properties
of films having varying percentages of a first embodiment of an
antimicrobial agent;
[0010] FIG. 6 is a chart showing the modulus and toughness of the
films of FIG. 5;
[0011] FIG. 7 is a chart showing the stress and strain properties
of films having varying percentages of a second embodiment of an
antimicrobial agent;
[0012] FIG. 8 is a chart showing the modulus and toughness of the
films of FIG. 7;
[0013] FIG. 9 is a chart showing the stress and strain properties
of films having varying percentages of a third embodiment of an
antimicrobial agent;
[0014] FIG. 10 is a chart showing the modulus and toughness of the
films of FIG. 9;
[0015] FIG. 11 is a side elevation of one embodiment of a laminate
according to the present disclosure;
[0016] FIG. 12 is an exploded side elevation of one embodiment of a
personal absorbent article;
[0017] FIG. 13 is a side cross-sectional view of one embodiment of
an absorbent article according to the present disclosure;
[0018] FIG. 14 is a schematic showing various steps of a zone of
inhibition test according to the disclosure; and
[0019] FIG. 15 is a schematic showing how test material is spread
onto a medium in the test of FIG. 14;
[0020] FIG. 16 is a chart showing how inulin enhances Lactobacillus
growth;
[0021] FIG. 17 is a chart showing a burst release of active agent;
and
[0022] FIGS. 18 and 19 are charts showing a sustained release of
active agent.
DETAILED DESCRIPTION
[0023] It is to be understood by one of ordinary skill in the art
that the present disclosure is a description of exemplary aspects
of the present disclosure only, and is not intended as limiting the
broader aspects of the present disclosure.
[0024] The term "laminate" refers to a material where a film
structure is adhesively or non-adhesively bonded to a web such as a
nonwoven or tissue material.
[0025] The term "meltblown fibers" refers to fibers formed by
extruding a molten thermoplastic material through a plurality of
fine, usually circular, die capillaries as molten threads or
filaments into a high velocity, usually heated, gas (e.g., air)
stream which attenuates the filaments of molten thermoplastic
material to reduce their diameter. In the particular case of a
coform process, the meltblown fiber stream intersects with one or
more material streams that are introduced from a different
direction. Thereafter, the meltblown fibers and other optional
materials are carried by the high velocity gas stream and are
deposited on a collecting surface. The distribution and orientation
of the meltblown fibers within the formed web is dependent on the
geometry and process conditions. Exemplary meltblown processes are
described in various patents and publications, including NRL Report
4364, "Manufacture of Super-Fine Organic Fibers" by V. A. Wendt, E.
L. Boone and C. D. Fluharty; NRL Report 5265, "An Improved Device
For the Formation of Super-Fine Thermoplastic Fibers" by K. D.
Lawrence, R. T. Lukas and J. A. Young; and U.S. Pat. No. 3,849,241
to Butin et al. and U.S. Pat. No. 5,350,624 to Georger et al., each
of which is incorporated herein by reference in a manner that is
consistent herewith.
[0026] The terms "nonwoven" and "nonwoven web" refer to materials
and webs of material having a structure of individual fibers or
filaments which are interlaid, but not in an identifiable manner as
in a knitted fabric. The terms "fiber" and "filament" are used
herein interchangeably. Nonwoven fabrics or webs have been formed
from many processes such as, for example, meltblown processes,
spunbond processes, air laying processes, wet layering processes
and bonded-carded-web processes.
[0027] The term "personal care absorbent articles" or "absorbent
articles" in the context of this disclosure includes, but is not
limited to, diapers, diaper pants, training pants, absorbent
underpants, incontinence products, and urinary shields; and the
like.
[0028] The terms "spunbond" and "spunbond fiber" refer to fibers
which are formed by extruding filaments of molten thermoplastic
material from a plurality of fine, usually circular, capillaries of
a spinneret, and then rapidly reducing the diameter of the extruded
filaments.
[0029] The term "% by weight," "weight %," "wt %" or derivative
thereof, when used herein, is to be interpreted as based on the dry
weight, unless otherwise specified.
[0030] These terms may be defined with additional language in the
remaining portions of the specification.
[0031] The present disclosure is generally directed to an extruded,
water-soluble, thermoplastic article into which an active agent has
been incorporated. The thermoplastic water-soluble, polymer from
which the article is made has an extrusion temperature of
90.degree. C. to 150.degree. C. The combination of the polymer and
active agent(s) is a homogeneous blend having an extrusion
temperature of 50.degree. C. to 125.degree. C. The articles made
from the homogeneous blend include films, fibers, pellets, or other
extruded shapes.
Materials
[0032] The materials from which the water-soluble, thermoplastic
material of the present disclosure is made generally include a
polymer and one or more active agents. Other optional materials
that improve the performance, look, feel and/or durability may be
added to the thermoplastic material.
[0033] Polymer:
[0034] Generally, the polymer used in the present disclosure is
polyvinyl alcohol (PVOH), polyethylene oxide (PEO), polyethylene
glycol (PEG), polyacylate (acid), polyacylamide, polyester, or a
combination of one or more of these polymers. Suitable polymers
have an extrusion temperature of 90.degree. C. to 150.degree.
C.
[0035] One desirable polymer is a highly amorphous vinyl alcohol
polymer, sold as "NICHIGO G-POLYMER," available from Soarus L.L.C.,
Arlington Heights, Ill. This particular polymer has a molecular
weight of 10,000 to 50,000, and a relatively low crystallinity of 5
to 25%.
[0036] In one aspect, a copolymer such as ethylene vinyl acetate
(EVA) may be combined with the base polymer. It is contemplated
that the article of the present disclosure may include up to 30% by
weight EVA. EVA aids in extrusion process, provides a means to
control the water dissolution speed, and lowers the overall cost of
the extruded material.
[0037] Active Agent:
[0038] In one aspect, the active agent is made from one or more
antimicrobial agents or skin benefit agents such as prebiotics,
humidity control material, skin pH-control material, a skin
protectant that mitigates skin irritation caused by feces/urine,
and combinations thereof. The biological agents may have varying
degrees of effectiveness, ranging from strict kill, selective kill,
no-kill, to prebiotic.
[0039] Suitable antimicrobials include biocides such as
benzoalkonium chloride ("BZK"), didecyl dimethyl ammonium chloride
("DDAC"), and zeolite ("CWT-A"). BZK in particular is a
broad-spectrum membrane disruptor that is inexpensive and
appropriate for both hard surface and skin disinfection.
[0040] Another suitable active agent is a botanical oil, and one
non-limiting example of a botanical oil is farnesol. Without being
bound by theory, it is believed that farnesol works by quorum
sensing control and targets yeast. One of the many benefits of
farnesol is that it provides a no-kill virulence control and it
comes from a botanical source.
[0041] Another suitable active agent is a botanical extract. One
non-limiting example of a botanical extract is a Yucca species
extract. The Yucca species extract ("Yucca") is a phenolic. Without
being bound by theory, it is believed that Yucca is a membrane
uncoupler and enzyme inhibitor. Yucca is a pathogen-selective
antifungal agent that can be incorporated directly into the film of
the present disclosure. One particular Yucca species is Yucca
schidigera which is a highly effective urease inhibitor (i.e.,
substances which inhibit production of ammonia from urine) when
applied directly to the skin. One source of Yucca schidigera powder
(100-percent pure) is sold under the trade designation DESERT PURE
YUCCA by Sher-Mar Enterprises of San Diego, Ca. Another source of
Yucca schidigera powder is sold under the trade designation
DINASE-30-DRY by Dinatec, Inc. of Gainesville, Ga. Information
relating to the efficacy of Yucca schidigera as a selective
antimicrobial may be found in U.S. Pat. No. 7,485,110, incorporated
herein to the extent it does not contradict the present
disclosure.
[0042] For aesthetic purposes, colorants may be incorporated into
articles containing Yucca to mask the relatively yellow and dark
color associated with bioactive levels of Yucca. One approach for
masking the color of Yucca is to co-extrude the film containing
Yucca as a core layer with (a) skin layer(s) on one side, or (b)
skin layer(s) on both sides. In this case, the skin layer(s)
contain pigments. For example, the yellow/dark color of yucca film
can be turned to white by adding suitable pigments into the skin
layer(s). To prepare a white skin, about 3 to 4 percent by weight
of the skin layer may be a titanium dioxide additive. To tint the
white skin a color, (e.g. purple, blue, or other color) pigment may
be added to the titanium dioxide additive.
[0043] Another suitable active agent is a prebiotic. Suitable
prebiotics are not antimicrobial in the sense that they kill a
specific pathogen, but instead they improve the growth of healthy
bacteria such as Bifidobacterium spp. or Lactobacillus spp. without
promoting growth of enteropathogenic bacteria. Only to that extent
are they considered "antimicrobial."
[0044] In one embodiment, the prebiotic comprises one or more
fructo-oligosaccharides. Fructo-oligosaccharides are generally
short-chain oligosaccharides comprised of D-fructose and D-glucose,
containing from three to five monosaccharide units.
Fructo-oligosaccharides act to stimulate the growth of
Bifidobacterium spp. or Lactobacillus spp.
[0045] In one embodiment, the prebiotic comprises one or more
inulins. Inulins are generally fructose-containing oligosaccharides
and belong to a class of carbohydrates known as fructans. Inulins
are especially useful to promote vulval/vaginal health as they
provide no-kill control of the microbiome. Inulins comprise
fructose units in a beta-(2-I) glucosidic linkage and comprise a
terminal glucose unit. The average degree of polymerisation of
inulins generally ranges from about 10 to 12.
[0046] Inulins stimulate the growth of Bifidobacterium spp. or
Lactobacillus spp. Referring to FIG. 16, demonstrated is how PVOH
releases glucose, starch, and inulin, providing for an increase in
growth of Lactobacillus spp. as compared to a PVOH film without an
added carbon source. Pure PVOH base film causes about 0.6 log value
growth of lactobacillus, which may come from the modifiers in the
polymer. To highlight the effect of inulin, the reference/base-line
from the PBS control shifts to the PVOH film. The pure contribution
from the inulin is almost 0.9 log which indicates that the delivery
approach is very effective.
[0047] Other possible active agents include: isothiazolone, alkyl
dimethyl ammonium chloride, a triazine, 2-thiocyanomethylthio
benzothiazol, methylene bis thiocyanate, acrolein, dodecylguanidine
hydrochloride, a chlorophenol, a quaternary ammonium salt,
gluteraldehyde, a dithiocarbamate, 2-mercatobenzothiazole,
para-chloro-meta-xylenol, silver, chlorohexidine, polyhexamthylene
biguanide, a n-halamine, triclosan, a phospholipid, an alpha
hydroxyl acid, 2,2-dibromo-3-nitrilopropionamide,
2-bromo-2-nitro-1,3-propanediol, iodine, bromine, hydrogen
peroxide, chlorine dioxide, chlorine, sodium hypochlorite, or
combinations thereof.
[0048] The amount of active agent that is loaded into an article is
limited due to the integrity of the resulting article structure. If
there is too much active agent in an article, it may be unduly
weakened. In one aspect, the sum of the active agent(s) is present
in a total amount of 0.1% to 50% by weight of the article, or a
total amount of 1% to 20% by weight of the article. In another
aspect, the sum of the active agent(s) is present in a total amount
of 2% to 10% by weight of the article.
[0049] Optional Materials:
[0050] Besides the components noted above, still other additives
may also be incorporated into the composition, such as fragrances,
melt stabilizers, dispersion aids (e.g., surfactants), processing
stabilizers, heat stabilizers, light stabilizers, UV stabilizers,
antioxidants, heat aging stabilizers, whitening agents,
antiblocking agents, antistatic agents, bonding agents, lubricants,
colorants, etc.
[0051] In one aspect of the present disclosure, the extruded
water-soluble article includes up to 50% thermoplastic starch by
weight. The starch acts as a filler to reduce the overall cost of
the extruded article. The extruded article may contain as much as
30% starch. One desirable water-soluble thermal starch is a
cellulose-based starch obtained from various plant sources,
hemicelluloses, modified cellulose (hydroxylalkyl cellulose,
cellulose ethers, cellulose esters, etc.), and the like. When a
starch is employed, the amount of such additional material may
range from about 0.1 wt. % to about 50 wt. % of the homogeneous
blend, in some embodiments from about 0.5 wt. % to about 40 wt. %,
and in some embodiments, from about 1 wt. % to about 30 wt. %.
[0052] Dispersion aids may also be employed to help create a
uniform dispersion of the active agent/plasticizer. When employed,
the dispersion aid(s) typically constitute from about 0.01 wt. % to
about 10 wt. % of the homogeneous blend, in some embodiments from
about 0.1 wt. % to about 5 wt. %, and in some embodiments, from
about 0.5 wt. % to about 4 wt. %.
[0053] The composition may also contain a preservative or
preservative system to inhibit the growth of microorganisms over an
extended period of time. Suitable preservatives may include, for
instance, alkanols, disodium EDTA (ethylenediamine tetraacetate),
EDTA salts, EDTA fatty acid conjugates, isothiazolinone, benzoic
esters (parabens) (e.g., methylparaben, propylparaben,
butylparaben, ethylparaben, isopropylparaben, isobutylparaben,
benzylparaben, sodium methylparaben, and sodium propylparaben),
benzoic acid, propylene glycols, sorbates, urea derivatives (e.g.,
diazolindinyl urea), and so forth. Other suitable preservatives
include those sold by Sutton Labs, such as "Germall 115"
(amidazoiidinyl urea), "Germall II" (diazolidinyl urea), and
"Germall Plus" (diazolidinyl urea and iodopropynyl butylcarbonate).
Another suitable preservative is Kathon CG.RTM., which is a mixture
of methylchloroisothiazolinone and methylisothiazoiinone available
from Rohm & Haas; Mackstat H 66 (available from McIntyre Group,
Chicago, Ill.). Still another suitable preservative system is a
combination of 56% propylene glycol, 30% diazolidinyl urea, 11%
methylparaben, and 3% propylparaben available under the name
GERMABEN.RTM. H from International Specialty Products of Wayne,
N.J.
[0054] To better enhance the benefits to consumers, other optional
ingredients may also be used. For instance, some classes of
ingredients that may be used include, but are not limited to:
antioxidants (for product integrity); astringents-cosmetic (for
inducing a tingling sensation on skin); colorants (for imparting
color to the product); deodorants (for reducing or eliminating
unpleasant odor and protect against the formation of malodor on
body surfaces); fragrances (for consumer appeal); skin conditioning
agents; and skin protectants (a drug product which protects injured
or exposed skin or mucous membrane surface from harmful or annoying
stimuli).
Method of Manufacture
[0055] In one aspect of the disclosure, a method of making an
extruded article may include the following steps. First, a
homogenous blend is formed by combining the polymer with at least
one active agent and possibly, one or more of the optional
ingredients described herein. In one desired embodiment, the
polymer is an amorphous, water-soluble vinyl alcohol as described
herein. Second, the homogeneous blend is extruded to form an
article.
[0056] The homogeneous blend has an extrusion temperature of
50.degree. C. to 125.degree. C., or possibly 90.degree. C. to
125.degree. C. This low extrusion-temperature profile is desirable
because some active agents of interest have poor thermal stability.
By using a low extrusion-temperature, a wider variety of active
agents may be incorporated into the homogenous blend.
[0057] Exemplary manufacturing equipment, a method of making
articles, and exemplary articles are described herein.
[0058] Extrusion Method:
[0059] The composition of the present disclosure is formed by
processing the components together in a melt-blending device (e.g.,
extruder). The mechanical shear and heat provided by the device
allows the components to be blended together in a highly efficient
manner without the use of a solvent. Batch and/or continuous melt
blending techniques may be employed in the present disclosure. For
example, a mixer/kneader, Banbury mixer, Farrel continuous mixer,
single-screw extruder, twin-screw extruder, roll mill, etc., may be
utilized. One particularly suitable melt-blending device is a
twin-screw extruder (e.g., PRISM USALAB .times.16, available from
Thermo Electric Co., Inc., New Jersey).
[0060] The polymer and the active agent(s), along with any optional
ingredients, form a homogeneous blend. For example, the materials
may be blended at a shear/pressure and temperature sufficient to
ensure adequate mixing (e.g., at or above the softening point of
the polymer), but without adversely impacting the physical
properties of the active agent. For example, melt-blending
typically occurs at a temperature of from about 50.degree. C. to
about 150.degree. C., in some embodiments from about 90.degree. C.
to about 130.degree. C., and in some embodiments from about
110.degree. C. to about 125.degree. C. These lower processing
temperatures prevent degradation of the active agent.
[0061] Once formed, the homogeneous blend of the present disclosure
may be used to create a variety of forms, such as films, fibers,
rods, bars or other shapes.
[0062] Films:
[0063] In one particular embodiment, the homogeneous blend is
formed into a film, either alone or in conjunction with an
additional film-forming material. The film may be used in a wide
variety of applications, such as a carrier of active agents for
medical products, garments, absorbent articles, etc. The film may
have a mono- or multi-layer configuration. Any known technique may
be used to form a film from the compounded material such as
extrusion coating, coextrusion of the layers, or any conventional
layering process.
[0064] The process to make the antimicrobial reservoir film is
relatively fast considering the high amounts of active agent that
can be added to the extrusion process. In one particular
embodiment, the film may be formed by flat die extrusion technique.
Processes for producing such extrusions are described, for
instance, in U.S. Pat. No. 7,666,337 to Yang et al.; U.S. Pat. No.
5,091,228 to Fuji et al; and U.S. Pat. No. 4,136,145 to Fuchs et
al.; all of which are incorporated herein in their entirety by
reference thereto for all purposes.
[0065] In yet another embodiment, however, the film is formed using
a casting or blowing technique.
[0066] Regardless of how the film is formed, it may be optionally
oriented in one or more directions to further improve film
uniformity and reduce thickness. For example, the film may be
immediately reheated to a temperature below the melting point of
one or more polymers in the film, but high enough to enable the
composition to be drawn or stretched. In the case of sequential
orientation, the "softened" film is drawn by rolls rotating at
different speeds or rates of rotation such that the sheet is
stretched to the desired draw ratio in the longitudinal direction
(machine direction). The film may be made into thicknesses ranging
from 0.01 mm up to about 1 mm, or in other aspects, from 0.05 mm to
0.20 mm.
[0067] The multi-layer film may contain from two (2) to nine (9)
layers, and in some embodiments from three (3) to five (5) layers.
In one example, the multi-layer film has one base layer and one
skin layer. The base layer and/or skin layer may contain the active
agent(s). The ratio between the layers may range from 1 to 20.
[0068] In another example, there is a three-layered film having a
core layer "C" that contains an active agent as described herein.
The outer skin layers "S" may act as a protective layer to the
core. The ratio between the layers may range from 2% to 98% of the
core layer and from 10% to 90% of the two combined skin layers. For
instance, the core layer may be up to about 30%, up to about 40%,
up to about 50%, up to about 60%, or up to about 70% of the total
thickness of the multi-layer film. Each skin layer may be up to
about 15%, or up to about 25%, or up to about 35% of the total
thickness of the multi-layer film.
[0069] The film, either mono- or multi-layered, may be wound and
stored on a take-up roll. Various additional potential processing
and/or finishing steps known in the art, such as slitting,
treating, aperturing, printing graphics may be performed.
[0070] In one aspect, the extruded water-soluble film has a basis
weight of 5 gsm to 500 gsm. In another aspect, the water-soluble
film has a basis weight of 20 gsm to 200 gsm.
[0071] In one aspect, the extruded water-soluble film has a tensile
strength of 0.5 MPa to 50 MPa according to the Tensile Test of the
present disclosure. In another aspect, the film has a tensile
strength of 1 MPa to 25 MPa according to the same test.
[0072] In one aspect, the extruded water-soluble film has a water
dissolution speed from 5 seconds to 30 minutes as determined by the
Water Dissolution Test of the present disclosure. In another
aspect, the extruded water-soluble article film has a water
dissolution speed of 30 seconds to 5 minutes as determined by the
same test.
[0073] In one aspect, the extruded water-soluble film has an
elongation of 5% to 500% according to the Tensile Test of the
present disclosure. In another aspect, the film has an elongation
of 10% to 100% according to the same test.
[0074] Articles:
[0075] The homogeneous blend of the present disclosure may also be
used to form other types of articles. In one aspect, the extruded
water-soluble article is a rod having a circular- or
elliptical-shaped extrusion profile. In another aspect, the
extruded water-soluble article is a rod having the geometric
extrusion profile of a polygon with three to ten sides (e.g. a
triangle to a decagon). The rod may be cut into pellets for later
processing.
[0076] Referring to FIG. 13, a laminate may be formed by extruding
the homogeneous blend 24 onto a carrier substrate 22, forming a
bond therebetween. The carrier substrate 22 may be a nonwoven or
woven material. The laminate may also be formed by adhering the
film of the present disclosure to a substrate using an adhesive.
Suitable adhesives include polyolefin-based hot melt construction
and elastic adhesives. Examples of suitable materials include
hydrophobic and hydrophilic hot melt polymers, such as those
available from Henkel (having a place of business located in
Bridgewater, N.J., U.S.A.) such as 34-5610, 34-447A, 70-3998 and
33-2058; those available from Bostik-Findley (having a place of
business located in Milwaukee, Wis., U.S.A.) such as HX 4207-01, HX
2773-01, H2525A, H2800, H9574; and those available from H.B. Fuller
Adhesives (having a place of business located in Saint Paul, Minn.,
U.S.A.) such as HL8151-XZP. Other adhesives are further described
in U.S. Patent Publication No. 2005/0096623 to Sawyer, et al.,
which is incorporated herein by reference in a manner that is
consistent herewith.
Applications
[0077] Absorbent Articles:
[0078] The film of the present disclosure is particularly suitable
for use in an absorbent article. An "absorbent article" generally
refers to any article capable of absorbing water or other fluids.
Examples of some absorbent articles include, but are not limited
to, personal care absorbent articles, such as diapers, training
pants, absorbent underpants, incontinence articles, feminine
hygiene products (e.g., sanitary napkins, pantiliners, etc.), swim
wear, baby wipes, and so forth; medical absorbent articles, such as
garments, fenestration materials, underpads, bedpads, bandages,
absorbent drapes, and medical wipes; food service wipers; clothing
articles; and so forth. Several examples of such absorbent articles
are described in U.S. Pat. No. 5,649,916 to DiPalma, et al.; U.S.
Pat. No. 6,110,158 to Kielpikowski; U.S. Pat. No. 6,663,611 to
Blaney, et al., which are incorporated herein in their entirety by
reference thereto for all purposes. Still other suitable articles
are described in U.S. Patent Application Publication No.
2004/0060112 A1 to Fell et al., as well as U.S. Pat. No. 4,886,512
to Damico et al.; U.S. Pat. No. 5,558,659 to Sherrod et al.; U.S.
Pat. No. 6,888,044 to Fell et al.; and U.S. Pat. No. 6,511,465 to
Freiburger et al., all of which are incorporated herein in their
entirety by reference thereto for all purposes. Materials and
processes suitable for forming such absorbent articles are well
known to those skilled in the art.
[0079] The present disclosure may be better understood with
reference to the examples presented herein.
[0080] First Exemplary Absorbent Article:
[0081] Referring to FIG. 12, in one aspect of the disclosure, a
personal absorbent article 30 includes an absorbent member 32
sandwiched between a water-impermeable backsheet 34 and a
water-permeable liner 36, wherein liner 36 has a body-facing
surface 38 and an opposite outward-facing surface 40. A film 41 of
the present disclosure is attached to either the outward-facing
surface 40 of the liner or a surface of the absorbent member 32
that is adjacent liner 36. Desirably, film 41 is in direct contact
with liner 36. Should a multi-layer film be used for film 41, the
layer containing the largest amount of active agent is adjacent
liner 36 so that the active agent can more easily leach through the
liner to contact the wearer's body.
[0082] As described, film 41 is made from materials that include a
water-soluble, polymer that may have an extrusion temperature of 90
to 150.degree. C.; a plasticizer; and one or more volatile active
agents in a total amount of 0.1% to 50% by weight of the
article.
[0083] Second Exemplary Absorbent Article:
[0084] Referring to FIG. 11, in one aspect, the film of the present
disclosure is laminated to other layers (e.g., nonwoven or
cellulose-fiber based web materials). One particular application of
a laminate structure is that of a three-layer wipe 100. In this
embodiment, the core layer 102 is a film containing at least the
active agent(s) of the present disclosure. Desirably, the outer
layers 104 and 106 that surround the core layer are natural or
synthetic fiber based web materials (e.g. tissue, paper, spunbond,
spunbond-meltblown-spunbond composite, coform, airlaid, etc.).
Other uses for laminates are contemplated, such as using the
laminate to manufacture garments such as disposable lab coats or
disposable booties. Another application may be to attach a piece of
a laminate onto a bathing sponge for imparting the active agents of
the disclosure to the skin while bathing.
[0085] Burst or Sustained Release Films:
[0086] Referring now to FIG. 17, shown is a release profile for a
BZK film having the following matrix: PVOH/EVA/Starch=54:13:33. It
is a "burst release" because it releases the active agent in about
1 to 3 minutes. It takes about 10 minutes for 100 percent of the
active to be released from the film. Sustained release films can be
created by varying the components of the film. Referring now to
FIG. 18, shown is a sustained release profile for BZK films having
varied matrixes: 100 percent PVOH; PVOH/EVA=80:20; and
PVOH/EVA/Starch=64:16:20. Each film contains 7 percent BZK by
weight. For the pure PVOH film, a release of 90 percent BZK takes
about 2 hours. Blending 20 percent EVA with the PVOH lowers the
release rate of BZK from the matrix: the time to release 90 percent
of the BZK is about 7 hours. Adding 20 percent starch to the
EVA/PVOH blend speeds the release rate of BZK to about 4 to 5
hours. Referring now to FIG. 19, shown is a sustained release
profile for BZK films having varied matrixes: 100 percent PVOH;
PVOH/EVA/Starch=48:32:20; PVOH/EVA/Starch=32:48:20; PVOH/EVA=60:40;
and PVOH/EVA=40:60. Each film contains 7 percent BZK by weight. For
the pure PVOH film, a release of 100 percent BZK takes about 5
hours. For the PVOH/EVA/Starch=48:32:20 film, a release of 100
percent BZK takes about 35 hours. For the PVOH/EVA/Starch=32:48:20
film, a release of 100 percent BZK takes about 65 hours. For the
PVOH/EVA=60:40 film, a release of 40 percent BZK takes about 48
hours. Finally, for the PVOH/EVA=40:60 film, a release of less than
5 percent BZK takes more than 70 hours.
Experimental Data
Experiment 1
[0087] Provided is experimental data for three antimicrobial agents
that act as biocides, namely, zeolite, benzoalkonium chloride, and
didecyl dimethyl ammonium chloride. Tests were performed on the
various codes for each biocide to determine dissolution, zone of
inhibition, and mechanical properties.
TABLE-US-00001 TABLE 1 Additives Category Code % GP25-C00 0
Inorganic biocide (zeolite) Sourced from: GP25-C05 5 Jishim Tech
Co., Lid (Korea), CWT-A GP25-C10 10 (brand name). GP25-C20 20
GP25-C50 50 Antimicrobial GP25-B01 1 BZK (benzoalkonium chloride)
Sourced Agents GP25-B02 2 from Mason Chemical, Company, IL,
GP25-B05 5 under NOBAC (brand name). GP25-B10 10 GP25-D01 1 DDAC
(didecyl dimethyl ammonium GP25-D02 2 chloride) Sourced from, Lonza
Inc, NJ, GP25-D05 5 BARDAC 2250 (brand name). GP25-D10 10
[0088] Films containing the various amounts of the antimicrobial
agents of Table 1 were made as follows. A twin-screw extruder
(PRISM USALAB .times.16, available from Thermo Electric Co., Inc.)
was used to make co-extruded film samples that contain an
antimicrobial agent. The extruder specifications were as follows:
[0089] 16 mm diameter screw [0090] L/D=40 (L=640 mm) [0091] 10
heating zones+die [0092] Maximum velocity=1000 rpm [0093] Maximum
pressure=100 bar [0094] Maximum torque=24 mN
[0095] The following extruder set-up was used to manufacture the
experimental film: [0096] Flat slit die width: 152.40 mm (6'')
[0097] Flat slit die height (controls film thickness): 0.127 mm
(0.010'')
[0098] Each coextruded film included one of the active ingredients
of Table 1.
[0099] The extruder feed zone was heated to 110.degree. C., the
following extruder zones 2-9 were heated to 125.degree. C., and the
die was heated to 130.degree. C. The material was extruded.
[0100] Dissolution Test:
[0101] I. Preparation of Specimens:
[0102] a. Cut 9 film specimens (approximately 0.75''.times.2.5'' or
0.07-0.12 g each). Record the mass of each specimen.
[0103] b. Match each specimen with a tall 2 oz glass jar and lid.
Fill each jar with enough buffered water so that the water is 100
times the weight of the film. Three jars are to be filled with a pH
5 buffered solution, three with a pH 7, and 3 with a pH 9 buffered
solution.
[0104] i. The buffered solutions contain:
[0105] 1. pH 5: 990 g tap water, 10 g sodium citrate, 1.89 g citric
acid
[0106] 2. pH 7: 990 g tap water, 10 g sodium citrate, 0.18 g citric
acid
[0107] 3. pH 9: 990 g tap water, 10 g sodium citrate, 1.02 g
triethanolamine
[0108] c. Heat one jar from each pH to 60.degree. C., and one jar
from each pH to 40.degree. C. The last jar of each pH remains at
room temperature (approx. 20.degree. C.)
[0109] II. Testing of Specimens:
[0110] a. Gather the film specimens, a stopwatch, a glass stir-rod,
and the jars of buffered water.
[0111] b. Drop a film specimen into each jar, using the glass rod
to submerge the film specimen if necessary. Do not drop the sample
onto the wall of the jar, as the film will adhere and take longer
to dissolve.
[0112] c. Start the timer immediately after submerging the film
specimen.
[0113] d. Record the time that the film is 95%+ dissolved. Swirl
the jar if necessary to check to see if the film is dissolved. Some
films cloud the water and make it difficult to discern when the
specimen is dissolved.
[0114] FIG. 1 is a three-dimensional graph showing the dissolution
time for antimicrobial GP25-C05, at varying pH and temperature. The
longest dissolution time of three minutes is shown at a condition
of pH 9 and 20.degree. C. In contrast, the shortest dissolution
time of less than 1 minute is shown at a condition of pH 5 and
60.degree. C.
[0115] Zone of Inhibition Test:
[0116] In this test method, the test material is brought into
contact with a known population of microorganisms on an agar plate
for a specified period of time. At the end of the contact time, the
area of inhibited colony formation around the test material is
measured. The size of this area of no growth is a measure of
leaching of the antimicrobial agent from the test material.
[0117] Referring to FIG. 14, the test material 200 is cut into
small discs and placed on an agar plate 202 evenly spread with a
test microorganism with a cotton swab 204. The plates are incubated
for 24 hours at ideal growth conditions. Following incubation, the
diameter of the circle of no growth 206 around the disc 200 is
measured. The zone of inhibition is reported as the difference
between the sample disc diameter and the average of the measured no
growth zone diameters.
[0118] Materials and Reagents: [0119] Microorganisms: frozen stock
of Staphylococcus aureus (ATCC 27660) and Pseudomonas aeruginosa
(ATCC 15442) Staphylococcus aureus (ATCC 6538), Escherichia coli
(ATCC 8739), and Candida albicans (ATCC 10231). [0120]
Mueller-Hinton agar (MHA) plates or equivalent plated media.
Prepare following manufacturer's directions. Store at
4.+-.2.degree. C. Alternatively, pre-made plates can be utilized.
[0121] Mueller-Hinton broth (MHB) or equivalent liquid media.
Prepare following manufacturer's directions. Store at
4.+-.2.degree. C. Alternately, pre-made media can be utilized.
[0122] Sterile cotton swabs or equivalent. [0123] Sterile forceps.
[0124] Positive control disc: Vanocymicin susceptibility discs (6
mm), 30 .mu.g/disc (BD and Company; Sparks, Md.). [0125] Test
material, cut into 8 mm discs. [0126] Calipers or other measuring
device. [0127] Other ancillary lab supplies.
[0128] Supply Set-Up:
[0129] 1. Label growth media plates appropriately for testing
codes.
[0130] 2. Sterilize test material discs with UV exposure in Laminar
flow hood for 15 minutes (both sides of disc), if required.
[0131] Inoculum:
[0132] 1. Take appropriate measures to ensure culture purity.
[0133] 2. Staphylococcus aureus or Pseudomonas aeruginosa is
inoculated from an overnight plate or MHB into 5 ml of sterile MHB
in a 35.degree. C. incubator for 18-24 hrs.
[0134] 3. The overnight culture is then adjusted using MHB to the
0.5 McFarland barium sulphate standards (1.times.108 CFU/ml) or
approximately 0.15 OD with a 0.2 cm light path at 660 nm.
[0135] 4. Discard the cell suspension if it is not used within 30
to 60 min after preparation.
[0136] Zone of Inhibition Bioassay Procedure:
[0137] 1. Pre-warm the MHA plates to room temperature. The number
of plates required per strain will depend on the number of test
materials to be tested and their anticipated zone inhibition
diameters; discs should be placed on plates so that zones of
inhibition do not overlap.
[0138] 2. The surface of the plates should be dry. If not, dry the
plates (with lids ajar) in a 35.degree. C. incubator for 20-30 min
just prior to inoculation. There should be no visible droplets of
moisture on the surface of the agar or on the lids of the plates
when they are inoculated.
[0139] 3. Moisten a sterile applicator swab in the standardized
cell suspension and express any excess moisture by rotating the
swab against the glass above the liquid in the tube. Referring to
FIG. 15, inoculate the entire surface of each agar plate 202,
inoculating the surface completely in three different directions
300, 302, 304 to ensure uniform growth.
[0140] (It is recommended that cotton swabs with wooden handles be
used for this procedure. Swabs made of synthetic materials do not
soak up sufficient suspension to inoculate the entire surface of
the plate. Swabs with plastic handles bend when excess suspension
is being expressed and may splatter liquid out of the tube.)
[0141] 4. Repeat step 10.3 to inoculate additional plates as
needed.
[0142] 5. Store the inoculated plates at room temperature for 10-15
min to allow the medium to absorb the moisture from the
inoculum.
[0143] 6. Apply discs of test material to the surface of the
inoculated medium with a sterile forceps and tap them to ensure
that they are in complete contact with the agar surface. A positive
control (vancomycin disc) and negative control (uncoated disc)
should be used on each plate. All discs should be approximately the
same distance from the edge of the plate and from each other (FIG.
14). In addition, all the discs should be positioned so the area of
no growth that may develop around them do not overlap.
[0144] 7. Invert the inoculated plates and incubate them at
35.degree. C. for 18-24 hours.
[0145] 8. Examine the plates from the back, viewed against a black
background and illuminated with reflected light. With calipers,
measure the diameter of each zone of inhibition to the nearest
whole millimeter.
[0146] Calculation:
[0147] The zone of inhibition is equal to the diameter of the
no-growth area minus the diameter of the disc.
[0148] The inhibition zone sizes given in this test protocol are
derived from test methods used at the Center for Disease Control as
well as AATCC Method 147-1998 (19) based on the National Committee
for Clinical Laboratory Standards (20-21) and ASTM E2149-01 step
12.2 (22). The diameters of zones of inhibition may vary depending
on many factors including medium base, humidity, and the age of the
medium. Thus, it is important to follow one protocol as closely as
possible to obtain results comparable between labs, personnel, and
experiments. It may be necessary to determine zone interpretative
sizes for disc diffusion results that are appropriate to local
conditions. These criteria may be determined with use of reference
strains and known challenge compounds and amounts.
[0149] Results:
[0150] FIG. 2 shows the result of the zone of inhibition testing
for films containing antimicrobial agent CWT-A. This agent was more
effective against Pseudomonas aeruginosa (Pa) than Staphylococcus
aureus (Sa), but the effectiveness against both microbes plateaued
when the film contained 20% or more of the antimicrobial agent.
[0151] FIG. 3 shows the result of the zone of inhibition testing
for films containing antimicrobial agent DDAC. This agent was
significantly more effective against Staphylococcus aureus (Sa)
than Pseudomonas aeruginosa (Pa). The effectiveness against Sa
microbes went from a zone of 4 mm to 14 mm between 0% and about 1%
DDAC. When the film contained from about 1% and 10% DDAC, the zone
of inhibition of the Sa microbes went from about 14 mm to about 17
mm. The effectiveness against Pa microbes went from a zone of 4 mm
to about 7 mm between 0% and about 1% DDAC. When the film contained
from about 1% and 10% DDAC, the zone of inhibition of the Pa
microbes went from about 9 mm to about 12 mm, plateauing at about 9
mm between about 1% and 4% DDAC.
[0152] FIG. 4 shows the result of the zone of inhibition testing
for films containing antimicrobial agent BZK. This agent was much
more effective against Staphylococcus aureus (Sa) than Pseudomonas
aeruginosa (Pa). The effectiveness against Sa microbes went from a
zone of 4 mm to 14 mm between 0% and about 1% BZK. When the film
contained from about 1% and 10% BZK, the zone of inhibition of the
Sa microbes went from about 15 mm to about 19 mm. The effectiveness
against the Pa microbes went from a zone of 4 mm to about 6 mm
between 0% and about 10% BZK.
[0153] Tensile Test: Prior to testing, samples were initially
conditioned at 75.degree. F./50% relative humidity for 24 hours.
Thereafter, the strip tensile strength values were determined in
accordance with ASTM Standard D-5034. A constant-rate-of-extension
type of tensile tester was employed. The tensile testing system was
a Synergie 200 tensile frame. The tensile tester was equipped with
TESTWORKS 4.08B software from MTS Systems Corp. to support the
testing. An appropriate load cell was selected so that the tested
value fell within the range of 10-90% of the full scale load. The
film samples were initially cut into dog-bone shapes with a center
width of 3.0 mm before testing. The samples were held between grips
having a front and back face measuring 25.4 millimeters.times.76
millimeters. The grip faces were rubberized, and the longer
dimension of the grip was perpendicular to the direction of pull.
The grip pressure was pneumatically maintained at a pressure of 40
pounds per square inch. The tensile test was run using a gauge
length of 18.0 millimeters and a break sensitivity of 40%. Five
samples were tested by applying the test load along the
machine-direction and five samples were tested by applying the test
load along the cross-direction. During the test, samples were
stretched at a crosshead speed of about 127 millimeters per minute
until breakage occurred. The modulus of elasticity, peak load, peak
stress, elongation (percent strain at break), and energy per volume
at break (total area under the stress-strain curve) were
measured.
[0154] The tensile test results showed that the films have
excellent mechanical properties for high-speed converting
processes. This allows the films to easily be placed into articles
such as the absorbent articles and laminates described herein.
[0155] Test Results:
[0156] FIGS. 5-10 show the test results from the tensile tests
described above.
[0157] Referring to FIG. 5, a dual chart shows how the stress and
strain vary with the percentage of antimicrobial in the tested
film, the antimicrobial being zeolite. The greatest break stress
occurs when the film contains 0% zeolite by weight. The break
stress drops rapidly as zeolite is added, and plateaus somewhat at
about 10% zeolite content by weight. Like the break stress, the
break strain is greatest when the film contains 0% zeolite by
weight, and generally plateaus after about 7% zeolite by weight has
been added.
[0158] Referring to FIG. 6, a dual chart shows how the elasticity
and toughness vary with the percentage of antimicrobial in the
tested film, the antimicrobial being zeolite. The greatest
elasticity occurs when the film contains 50% zeolite by weight. The
least amount of elasticity is seen at about 10% by weight zeolite.
Like the break stress, toughness is greatest when the film contains
0% zeolite by weight, and generally plateaus after about 10%
zeolite by weight has been added.
[0159] Referring to FIG. 7, a dual chart shows how the stress and
strain vary with the percentage of antimicrobial in the tested
film, the antimicrobial being benzoalkonium chloride. The greatest
break stress occurs when the film contains 0% benzoalkonium
chloride by weight. The break stress drops as benzoalkonium
chloride is added, and plateaus somewhat at about 5% benzoalkonium
chloride content by weight. Unlike the break stress, the break
strain is greatest when the film contains 10% benzoalkonium
chloride by weight, and generally plateaus when between about 1%
and 5% benzoalkonium chloride by weight has been added.
[0160] Referring to FIG. 8, a dual chart shows how the elasticity
and toughness vary with the percentage of antimicrobial in the
tested film, the antimicrobial being benzoalkonium chloride. The
greatest elasticity occurs when the film contains 4% benzoalkonium
chloride by weight. The least amount of elasticity is seen at about
10% by weight benzoalkonium chloride. Unlike the break stress,
toughness is greatest when the film contains 10% benzoalkonium
chloride by weight. A sharp rise from its lowest toughness occurs
at about 4% benzoalkonium chloride by weight.
[0161] Referring to FIG. 9, a dual chart shows how the stress and
strain vary with the percentage of antimicrobial in the tested
film, the antimicrobial being didecyl dimethyl ammonium chloride.
The greatest break stress occurs when the film contains 0% didecyl
dimethyl ammonium chloride by weight. The break stress drops as
didecyl dimethyl ammonium chloride is added, with only a small
plateau between about 1 to 2% didecyl dimethyl ammonium chloride by
weight. Like the break stress, the break strain is greatest when
the film contains 0% didecyl dimethyl ammonium chloride by weight,
and drops somewhat steadily as it is added.
[0162] Referring to FIG. 10, a dual chart shows how the elasticity
and toughness vary with the percentage of antimicrobial in the
tested film, the antimicrobial being didecyl dimethyl ammonium
chloride. The greatest elasticity occurs when the film contains
either 0% or 10% didecyl dimethyl ammonium chloride by weight. The
least amount of elasticity is seen at about 2% by weight didecyl
dimethyl ammonium chloride. Like the break stress, toughness is
greatest when the film contains 0% didecyl dimethyl ammonium
chloride by weight. TH toughness drops steadily after 2% didecyl
dimethyl ammonium chloride by weight has been added to the film,
following a minor plateau between the 1% and 2% didecyl dimethyl
ammonium chloride by weight has been added to the film.
Experiment 2
[0163] Inulin was included in PVOH films and tested for an increase
in growth of Lactobacillus spp. as compared to a PVOH film without
an added carbon source. A 48-hour culture of Lactobacillus
acidophilus ATCC 314 was added to a 6 well microplate containing
controls and films of specified size for PVOH and PVOH+Inulin.
Phosphate buffer solution and media (LAPT-Glucose) with L.
acidophilus (.about.4.5 LOG.sub.10 CFU/mL) were added to wells
containing PVOH films. The 6-well plate was incubated at 37.degree.
C. for 24 hours, removed, and the solutions were diluted
appropriately and plated. After 48 hours of incubation at
37.degree. C., the plates were removed and counted for results.
FIG. 16 demonstrates how PVOH is able to release inulin and
provides an increase in growth of Lactobacillus spp. as compared to
a PVOH film without an added carbon source.
[0164] The testing results indicated that the pure PVOH base film
also caused about 6.1 LOG.sub.10 (CFU/mL) growth of lactobacillus,
which could come from the modifiers in the G-polymer. To highlight
the effect of inulin, the pure contribution from the inulin is near
0.9 LOG 10 (CFU/mL) growth over the PVOH film without an added
carbon source, which indicates the delivery approach is very
effective and the prebiotic is still active.
Test Method
Materials
[0165] Lactobacillus acidophilus ATCC 314 [0166] Lactobacilli MRS
broth, 500 g, Fischer Sci DF 0881-17-5 [0167] Difco Lactobacilli
MRS agar, 500 g, Fisher DF 0882170 [0168] Phosphate buffer (Remel
with Magnesium chloride) [0169] Crystalgen Bio-Degradable Green
Culture Flasks, 125 ml (Fisher 05-539-804) [0170] BD.TM. Difco.TM.
Disposable Inoculating Needles 10 .mu.l; Light blue; Pack of 250
(Fisher 22-031-22) [0171] 15 mL centrifuge tube [0172] GasPack EX
anaerobe sachets, Fischer B-260678
Culture
[0172] [0173] 1. Aseptically add 20 mL of MRS broth to a
disposable, sterile culture flask [0174] 2. Remove test organism
from -80.degree. C. [0175] 3. Using 1 (10 .mu.L) disposable loop,
remove a single bead from stock and add to the broth [0176] 4. Grow
for 48 hours, 37.degree. C., static conditions [0177] 5. Remove
flask from incubator; assume starting concentration organism is
10.sup.7-8 CFU/mL
Experimental
[0177] [0178] 1. Centrifuge & wash 48 hour grown cells 1.times.
with 20 ml PBS; 8,000 rpm (10,322 g) for 10 minutes at 4.degree. C.
[0179] 2. Dilute 1:100 in PBS (10 uL into 990 uL) [0180] 3. Dilute
1:100 in LAPT-G media (glucose depleted) (140 ul into 13.0 mL)
[0181] 4. Determine concentration of inoculum by plating out -1,
-2, -3 on MRS agar plates, incubate anaerobically 2 days.
Day 1a: 6-Well Plate Set-Up
[0181] [0182] 1. Set-up 2 replicate plates for each code [0183] Add
1.0 ml PBS to wells containing PVOH films [0184] Add 1.0 ml
inoculum (L. acidophilus in LAPT-G) to all wells
Day 1b: Incubation of 6-Well Plate
[0184] [0185] 1. Place 6-well plate and inoculation plates into
anaerobic box; place plate lid slightly askew [0186] 2. Add 3
packages BD Gas Pak EZ anaerobe container system packs into box and
close lid [0187] 3. Incubate 24 hours at 37.+-.2.degree. C.
Day 2: Incubation of 6-Well Plate
[0187] [0188] 1. Dry MRS lab made plates in laminar flow cabinet
15-30 minutes [0189] 2. Prepare dilutions in PBS [0190] 3. Plate
out samples and controls from 6-well plate in duplicate [0191] 4.
Incubate plates 48 hours, as described above (37.+-.2.degree. C.,
anaerobic conditions)
Day 4: Results
[0191] [0192] 1. Count MRS plates and record results. As will be
appreciated by those skilled in the art, changes and variations to
the present disclosure are considered to be within the ability of
those skilled in the art. Examples of such changes are contained in
the patents identified above, each of which is incorporated herein
by reference in its entirety to the extent it is consistent with
this specification. Such changes and variations are intended by the
inventors to be within the scope of the present disclosure. It is
also to be understood that the scope of the present disclosure is
not to be interpreted as limited to the specific aspects disclosed
herein, but only in accordance with the appended claims when read
in light of the foregoing disclosure.
* * * * *